Habka synthetic ee hydroxypropyl methylcellulose

Guud ahaan, in falgalka eehydroxypropyl methylcellulose, cellulose suufka la safeeyey waxaa lagu daaweeyaa xalalka alkali at 35-40 ° C nus saac, tuujin, cellulose waa la miiray, oo ku habboon da'da at 35 ° C, si fiilooyinka alkali helay celcelis ahaan shahaado polymerized waa in xadka loo baahan yahay. Geli fiber alkali kettle etherification, ku dar propylene oxide iyo methyl chloride markeeda, oo ka ether ka 50-80 ℃ ilaa 5 saacadood cadaadis sare oo qiyaastii ah 1.8 MPa. Kadibna ku dar qadar ku habboon oo ah hydrochloric acid iyo oxalic acid biyaha kulul ee 90 ° C si aad u dhaqdo walxaha si loo kordhiyo mugga. Ku fuuqbaxa centrifuge. Ku dhaq ilaa dhexdhexaad, marka biyaha ku jira maaddadu ay ka yar tahay 60%, ku qalaji socodka hawo kulul 130 ° C ilaa in ka yar 5%.

Alkalization: Cudbiga la safeeyey ee budada ah ka dib marka la furo waxaa lagu daraa dareere aan firfircooneyn, waxaana lagu hawlgeliyaa alkali iyo biyo jilicsan si ay u bararaan shabagga crystal ee suufka la safeeyey, taas oo u sahlaysa dhexgalka molecules wakiilka etherifying oo wanaajinaya isku mid ahaanshaha falcelinta etherification. Alkalization-ka loo isticmaalo alkalization waa bir hydroxide ama saldhig organic. Qadarka alkali ee lagu daray (cusub, isla hoos) waa 0.1-0.6 jeer ka badan suufka la safeeyey, iyo xaddiga biyaha jilicsan waa 0.3-1.0 jeer ka badan suufka la safeeyey; dareeraha qallafsan waa isku dhafka khamriga iyo hydrocarbon, iyo qadarka dareeraha aan shaqaynayn ee lagu daray waa suuf la safeeyey. 7-15 jeer: dareeraha qallafsan wuxuu kaloo noqon karaa aalkolo leh 3-5 atamka kaarboon (sida khamriga, propanol), acetone. Waxa kale oo ay noqon kartaa hydrocarbons aliphatic iyo hydrocarbons udgoon; heerkulka waa in lagu xakameeyo gudaha 0-35 ° C inta lagu jiro alkalization; waqtiga alkalization waa ilaa 1hr. Hagaajinta heerkulka iyo waqtiga waxaa lagu go'aamin karaa iyadoo loo eegayo shuruudaha alaabta iyo alaabta.

Etherification: Daawaynta alkalization ka dib, xaaladaha faakuumka, etherification waxaa lagu fuliyaa iyadoo lagu darayo wakiilka etherifying, iyo wakiilka etherifying waa propylene oxide. Si loo yareeyo isticmaalka wakiilka etherifying, wakiilka etherifying ayaa lagu daray laba jeer inta lagu jiro habka etherification.


Waqtiga boostada: Abriil-28-2024